The present invention relates to a magnetic disk device, and in particular to a magnetic disk device having a magnetic head supporting mechanism including at least an IC for amplifying information on a magnetic head unit.
Conventionally, an IC is arranged in opposed relation with a disk surface in order to cool the IC while maintaining the distance of not more than 1 mm between the disk and the IC as disclosed in JP-A-11-195215.
Also, JP-A-11-296803 discloses a magnetic disk device in which a control circuit connected to an IC, after supplying a write current to the magnetic head unit for a predetermined length of time, prevents the write current from flowing to the magnetic head unit for a suspension time not shorter than the particular predetermined length of time.
In arranging an IC in opposed relation to the disk surface, various problems are liable to occur. For example, the length of the wiring (flexible print circuit: FPC) laid between the IC and the magnetic head unit is restricted, the disk may be damaged by the IC and the disk coming into contact with each other under an external shock, and the IC junction facing down makes the pattern inspection (electrical inspection) difficult.
Also, the cooling effect (ability) of the air flow with the disk rotation is varied with the radial position of the IC. Thus, the time during which the continuous write operation can be performed on the magnetic head unit is different depending on the radial position of the IC. If the continuous write time and the suspension time are determined without taking the cooling ability depending on the radial position of the IC into account, therefore, the continuous write time may be limited to a time length which is provided when the IC is located at the inner peripheral position which is low in cooling ability. As a result, the otherwise available continuous write time (ability) based on the high cooling ability with the IC located on the outer peripheral position may fail to be used, resulting in a reduced utilization rate.
In order to solve the problems described above, the object of the present invention is to provide means for maintaining the temperature rise of the IC not higher than a tolerable temperature without arranging the IC chip in opposed relation to the disk surface.
According to one aspect of the invention, there is provided a magnetic disk device comprising an IC mounted on a magnetic head supporting mechanism, for amplifying the information write/read signal on the magnetic head unit, and a control circuit connected with the IC, wherein the power consumption for the write/read operation is controlled in accordance with the head position on the magnetic disk by the control circuit thereby to maintain the IC temperature at a level not higher than a predetermined temperature.